From 2236284bcbd4e1652ca687e8642b617b73df5be9 Mon Sep 17 00:00:00 2001
From: Dan White <dan@whiteaudio.com>
Date: Mon, 23 Apr 2012 17:28:36 -0500
Subject: [PATCH] cleanup dac class

---
 python-lib/usbio.py | 129 +++++++++++++++++++++++++++-----------------
 1 file changed, 80 insertions(+), 49 deletions(-)

diff --git a/python-lib/usbio.py b/python-lib/usbio.py
index b7eeb40..c84f5d9 100644
--- a/python-lib/usbio.py
+++ b/python-lib/usbio.py
@@ -515,71 +515,82 @@ class AD524x(object):
 
 
 
-class DAC_Channel(object):
-    def __init__(self, defaults):
-        self._value = defaults['value']
 
-    @property
-    def value(self):
-        return self._value
 
-class DAC_word(object):
-    """
-    Container for (easily) constructing an appropriate 32-bit DAC8568 command.
-    """
+class DAC8568(object):
+    CTL_WIDTH = 32
+    DAC_WIDTH = 16
+    POR_VALUE = 2**(DAC_WIDTH - 1)
+
     ALL_CHANNELS = 0xf
 
-    def __init__(self):
-        self._word = intbv(0)[32:]
+    # Clear Code Register values
+    CLEAR_TO_ZERO = 0
+    CLEAR_TO_MID = 1
+    CLEAR_TO_FULL = 2
+    IGNORE_CLR = 3
+
+    # DAC channel writing modes
+    INPUT = 0
+    UPDATE = 1
+    INPUT_UPDATE_ALL = 2
+    INPUT_UPDATE_SINGLE = 3
+
+    # channel power modes
+    POWER_ON = 0
+    POWER_OFF_1k = 1
+    POWER_OFF_100k = 2
+    POWER_OFF_HIZ = 3
+
+    # internal reference modes
+    REF_STATIC_OFF          = 0x08000000
+    REF_STATIC_ON           = 0x08000001
+    REF_FLEXIBLE_ON         = 0x09080000
+    REF_FLEXIBLE_ALWAYS_ON  = 0x090a0000
+    REF_FLEXIBLE_ALWAYS_OFF = 0x090c0000
+    REF_TO_STATIC_MODE      = 0x09000000
+
+    def __init__(self, spibus, cs='dac'):
+        self.bus = spibus
+        self.cs = 'dac'
+        self._word = intbv(0)[self.CTL_WIDTH:]
+
+    def __str__(self):
+        return ''.join(map(chr, self.bytes()))
 
     @property
     def word(self):
         return self._word
 
-    #prefix bits are 0xxx always
-    #def prefix(self, value):
-    #    self._word[32:28] = intbv(value, max=2**4)
-
-    def control(self, value):
-        self._word[28:24] = intbv(value, max=2**4)
-
-    def address(self, value):
-        self._word[24:20] = intbv(value, max=2**4)
-
-    def data(self, value):
-        self._word[20:4] = intbv(value, max=2**16)
-
-    def feature(self, value):
-        self._word[4:0] = intbv(value, max=2**4)
+    def CCR(self, mode):
+        self._clear()
+        self._control(0x5)
+        self._feature(mode)
 
     def LDAC(self, bitfield):
-        self.reset()
-        self.control(0x6)
+        self._clear()
+        self._control(0x6)
         self._word[8:0] = intbv(bitfield, max=2**8)
 
-    def reset(self):
-        self._word = intbv(0)[32:]
-
+    def swreset(self):
+        self._clear()
+        self._control(0x7)
 
-class DAC8568(object):
-    CTL_WIDTH = 32
-    DAC_WIDTH = 16
-    POR_VALUE = 2**(DAC_WIDTH - 1)
+    def set(self, addr, value, mode):
+        self._clear()
+        self._control(mode)
+        self._address(addr)
+        self._data(value)
 
-    def __init__(self, spibus, cs='dac'):
-        self.bus = spibus
-        self.cs = 'dac'
-        self._word = intbv(0)[self.CTL_WIDTH:]
-    
-    def __str__(self):
-        return ''.join(map(chr, self.bytes()))
+    def power(self, mode, bitfield):
+        self._clear()
+        self._control(0x4)
+        self._word[10:8] = intbv(mode, max=2**2)
+        self._word[8:0] = intbv(bitfield, max=2**8)
 
-    def updateall(self, value):
-        v = intbv(value, max=self.DAC_WIDTH)
-        d = intbv(0)[32:]
-        d[28:24] = 0x3
-        d[24:20] = 0xf
-        d += (v << 4)
+    def reference(self, mode):
+        self._clear()
+        self._word = intbv(mode, max=2**32)
 
     def bytes(self):
         """Return the control data as a byte sequence in MSB..LSB order."""
@@ -592,6 +603,26 @@ class DAC8568(object):
         self.bus.Start()
         self.bus.Write(str(self))
         self.bus.Stop()
+
+    #
+    # internal functions to help construct a command
+    #
+    def _clear(self):
+        self._word = intbv(0)[32:]
+
+    def _control(self, value):
+        self._word[28:24] = intbv(value, max=2**4)
+
+    def _address(self, value):
+        #other values are no-op addresses
+        if (value <= 7) or (value == 15):
+            self._word[24:20] = intbv(value, max=2**4)
+
+    def _data(self, value):
+        self._word[20:4] = intbv(value, max=2**16)
+
+    def _feature(self, value):
+        self._word[4:0] = intbv(value, max=2**4)
         
 
 
-- 
2.25.1